Lord Belstead

Lord Belstead, who has died aged 73, made virtues of very hard and careful work and avoiding publicity. Long after he had risen to succeed Lord (Willie) Whitelaw as Margaret Thatcher's leader of the Lords in 1988, few in the country could even recognise his title.

His more flamboyant father, Francis Ganzoni, had given up the Swiss-Italian family name when he entered the Lords as the 1st Baron Belstead. A barrister by training, the long-serving Conservative MP for Ipswich made his Commons reputation by improving the MPs' dining room, which became known as Chez Ganzoni. When war clouds gathered, the family name became an embarrassment. Francis turned into a super-patriot in compensation and was tagged "Union Jack Ganzoni". Neville Chamberlain relieved him of the embarrassment by elevating him to the Lords in 1938.

His only son, John Julian Ganzoni, showed no interest in imitating his father. He attended Eton and Christ Church, Oxford, before becoming a history master at Selwyn House, an East Sussex boarding prep school. When his father's death in 1958 made him the 2nd Baron Belstead, he used his inheritance to buy a 650-acre farm near Woodbridge, Suffolk, where he raised cereal crops and sugarbeet, and started a small single-suckler herd.

He was tempted into the Lords by his teaching background, making his maiden speech in 1964 on the Newsom report, welcoming its raising of the school-leaving age to 16, but only if there were "more teachers and better buildings". Later, he urged that this be deferred until funds were found by increasing the cost of school meals or delaying the Open University.

When Edward Heath was forming his first Conservative government in 1970, Belstead was named as an undersecretary in Thatcher's education team. His report card in the magazine Education read: "It is doubtful if anyone at the DES has ever been more genuinely interested in the nitty-gritty of education." He polished up the educational handles so carefully that he was transferred to the same ministerial post in Northern Ireland, which he held from 1973 to 1974. When the February 1974 election was called, Francis Pym and others went off to fight the general election, leaving Ulster in Belstead's safe hands.

Labour unexpectedly won that election and Belstead kept his anonymity - despite becoming the Tories' spokesman in the Lords on education, industry, trade, consumer affairs and Northern Ireland. Though a strain, even for a workaholic, his ability to avoid putting a foot wrong guaranteed his obscurity.

When Thatcher came to power in 1979, Belstead was again named an undersecretary, this time replying on the gamut of subjects handled in the Commons by Whitelaw, then home secretary, and his three departmental ministers. Promoted to the Foreign Office in 1982, Belstead made his one slip of the tongue to attract attention. On a visit to Istanbul, he said how pleased he was to be in Constantinople, an easy error for a former history master, but not one Turkish journalists could forgive.

Belstead's next promotion, the following year, was as deputy leader of the Lords, underpinning the ennobled Whitelaw, and also minister of state for agriculture. Although he did much of the work for which Whitelaw got the credit, it was not until 1988, by which time his boss's health had deteriorated, that Belstead became leader of the Lords. For lobby correspondents in off-the-record weekly briefings, there was a shift from Whitelaw's bluster to Belstead's quiet courtesy and honesty.

When John Major became prime minister in 1990, he demoted Belstead to Northern Ireland minister, with the payroll title of paymaster general. This lasted for two years, when he left government to become chairman of the Parole Board, a job he loved, he told me, and held from 1992 to 1997. By that time he had tired of politics, especially Conservative politics.

· John Julian Ganzoni, 2nd Baron Belstead and Baron Ganzoni, politician, born September 30 1932; died December 3 2005